The present invention relates generally to the field of industrial control and monitoring networks, and to network connections within such environments. More particularly, the invention relates to a branch connector designed to permit devices to be coupled independently to a network for receiving control and monitoring signals, as well as power signals, without interruption of similar signals to other devices of the network.
A range of networks are known and are currently in use throughout industrial, consumer, and other applications. In many networks, data signals and power signals are transmitted separately to network devices. That is, the devices are coupled to computers or other data processing equipment or peripherals, and are separately coupled to a source of electrical power, such as a wall outlet. In industrial settings, specialized networks are often used which supply both data and power in a single set of connections. For example, in a network system of a current design, direct current power is available via a network cable, as are data signals. The cabling permits both power and data signals to be transmitted to and from the network devices. Thus, input and output modules can serve to apply control signals to network devices, or to receive feedback signals from the devices for carrying out complex control and monitoring functions.
In control and monitoring networks of the type described above, particular problems arise in the permanent or temporary addition of devices to the network. In a prefabricated enclosure, for example, specific connection points may be provided for the various original devices, with individual cable assemblies being routed from the connection points to the devices for normal operation. In general, it has been found desirable to route such cabling independently, so as to permit devices to be connected to the network or removed from the network without affecting application of power of data signals to downstream devices. However, after initial assembly or installation it may be found that an inadequate number of connection points may be available within the system or enclosure.
By way of example, when a new device or a temporary device is added to a control and monitoring network, a special connection may be required in addition to those already provided. The connection thus would require that the existing cabling be cut or tapped for terminating the new connector. Such procedures may be undesirable in settings where control and monitoring functions are carried on in real time and where making the connections may affect overall processes, such as manufacturing, material handling, and so forth. Certain industrial networks also enable monitoring functions to be carried out on temporarily connected devices, such as laptop computers, human interface modules, and the like. Where a connection is not available for such devices, however, a special connection may be installed as before, or one or more of the devices of the network may need to be disconnected to accommodate the temporary connection. Again, such interruption of service is often undesirable.
In addition to the foregoing considerations, certain enclosed systems, such as motor control centers, may include a series of bays with different types of equipment or networked devices installed in each bay. Certain of the devices may be coupled to higher voltages, such as for supplying power to specific loads controlled by the system. Even where additional connections are available in such bays, it may be desirable to add devices, or to service the system via temporary devices in a different bay where no additional connection is available.
There is a need, therefore, for a straightforward technique for accommodating additional or temporary connections in control and monitoring networks. There is a particular need for a connector system which will permit back-compatibility to existing systems, while enabling rapid and reliable connections to be made for additional or temporary devices without interrupting data and power signals to existing network devices.